Is it permissible to seek a different Wali or allow the girl to make her own choice if the father opposes temporary marriage and is unwilling to consider it?
Wali of virgin girl is her real father or her paternal grand father. No one else can be Wali for virgin girl. If the father opposes a marriage with a comparable Momin for no valid reason, and the girl needs the marriage to protect herself from sin, then she can refer to her Marje' of Taqleed to seek his verdict in such situation.
'Wassalam.